Meta-Analysis Points to Benefits of Staged PCI for Nonculprit Lesions

Marlene Busko

November 01, 2012

TORONTO — A meta-analysis sheds further light on a day-to-day question facing interventional cardiologists: what to do with nonculprit lesions found in a patient with ST-segment-elevation MI (STEMI) [1]? Although guidelines are clear about not treating nonculprit lesions along with the culprit lesion, they do not address whether it is harmful or beneficial to treat any of the discovered partly stenosed vessels later on.

This analysis of 26 heterogeneous, mainly observational studies of patients with STEMI and multivessel CAD found that patients had lower mortality rates when PCI was performed on nonculprit lesions as a staged procedure.

When nonculprit lesions were tackled concurrently with the primary culprit lesion, patients had a greater risk of in-hospital mortality.

"We've clearly shown that if you do other lesions at the time of the first procedure, it's dangerous," said Dr Kevin Bainey (Mazankowski Alberta Heart Institute, Edmonton), in a comment to heartwire after presenting here at the Canadian Cardiovascular Congress 2012.

"The question the guidelines don't address is, 'Can you deal with these lesions at a later time?' " he said. Their meta-analysis showed that the answer is "yes," Bainey remarked, adding that the definitive answer remains to be determined in a large, randomized trial, such as the COMPLETE trial, which will be undertaken by a team at McMaster University in Hamilton, ON, and which plans a four-year follow-up.

"Bread-and-Butter" Question

About 40% to 70% of patients undergoing primary PCI have multivessel disease and increased risk of death, Bainey said. There would appear to be pros and cons for taking care of these nonculprit lesions. On the one hand, "patients and physicians [might] just feel comfortable, knowing nonculprit lesions have been treated," he said. On the other hand, this strategy "may cause instability in a patient when he or she is already sick," and moreover, patients in distress just "want it done" as quickly as possible.

As reported earlier by heartwire , ACC/AHA and ESC treatment guidelines are based on existing, lower-quality evidence, and they advise clinicians to leave nonculprit lesions alone.

To investigate treating vs not treating nonculprit lesions in patients with STEMI and multivessel disease, the researchers conducted a meta-analysis of relevant published and unpublished studies.

They identified 26 studies of more than 46 000 patients who underwent either multivessel PCI (7886 procedures) or PCI of only the culprit lesion (38 438 procedures).

Of the 26 studies, only three were randomized, and these were very small trials.

The findings of this hypothesis-generating meta-analysis suggest that staged PCI on nonculprit lesions may offer significant clinical benefits, Bainey summarized. They also imply that "it doesn't matter if the patients are staged as inpatients or as outpatients," he added, speculating that it may turn out to be cost saving to treat these patients as outpatients.

"Emotional Reaction" to Lesions

Commenting on this study, comoderator Dr Eric Cohen (Sunnybrook Hospital, Toronto, ON) told heartwire that it provides a valuable review of the existing literature and highlights knowledge gaps about how to handle nonculprit lesions. "This is a very bread-and-butter, day-to-day question," he noted. "As primary PCI for STEMI has become more common, we're all facing this."

According to Cohen, current practices for dealing with nonculprit lesions vary widely, and interventional cardiologists tend to have an "emotional reaction" to lesions in other vessels, which leads them to want to intervene on them.

"We've learned pretty well that they shouldn’t be touched during the index procedure unless the patient is in shock, but there are a lot of patients who get brought back to the cath lab the next day or later in the same admission, [and] we don't really have definitive evidence either way," he said.

Although the current study demonstrated "apparent advantages to going ahead and intervening, there are some well-known potential disadvantages as well," he noted. "Recommendations come down on the more cautious side, which says that in the absence of recurrent symptoms or some form of evidence for ischemia, those patients should be left alone."

It will likely take a while and several randomized trials to clearly answer this highly relevant question, he concluded.

The authors declared they have no conflict of interest.